Cable connector

ABSTRACT

An electrical connector having a pair of telescopically engageable housings in which the ends of single or double pole conductors to be connected are enclosed. A tulip-type connector is mounted on the enclosed end of one of the conductors for engagement with the end of the other conductor when the housings are telescopically engaged. The operative end face of the housing enclosing the tulip connector is constructed to present a dead front to prevent accidental contact with the live conductor with one&#39;&#39;s finger or a tool, such as a screwdriver. The housings and the ends of the conductors are constructed to minimize arcing between the conductors to a maximum extent when the connector is coupled and uncoupled under load.

United States atent Kinnear May 28, 1974 1 CABLE CONNECTOR 3,120,987 2/1964 Degnan et al. 339/60 M [76] Inventor: Joseph D. Kinnear, 3019 E. Miles [22] Filed: Apr. 18, 1972 [21] Appl. No.: 245,138

Related U.S. Application Data [63] Continuation-impart of Ser. No. 57,568, July 23,

1970, abandoned.

[52] U.S. Cl. 339/64 R, 339/186 R, 339/255 R [51] Int. Cl H0lr 13/62 [58] Field of Search 339/59-61; 339/64-66, 186, 187 255 [56] References Cited UNITED STATES PATENTS 1,222,72] 4/l9l7 Bissell et al. 339/64 R 2,265,006 12/1941 Rubel et al.'.... 339/64 R 2,356,752 8/1944 Deysher 1 339/66 M 2,386,611 10/1945 lleman 1 339/255 R 3,023,394 2/1962 Hubbell 339/186 M 3,097,904 7/1963 Yarrick et al 339/64 R Rd., Warren, Mich.

Primary Examiner-Joseph H. McGlynn Attorney, Agent, or FirmBarnes, Kisselle, Raisch &

Choate [57] ABSTRACT An electrical connector having a pair of telescopically engageable housings in which the ends of single or double pole conductors to be connected are enclosed. A tulip-type connector is mounted on the enclosed end of one of the conductors for engagement with the end of the other conductor when the housings are telescopically engaged. The operative end face of the housing enclosing the tulip connector is constructed to present a dead front to prevent accidental contact with the live conductor with ones finger or a tool,

' such as a screwdriver. The housings and the ends of the conductors are constructed to minimize arcing between the conductors to a maximum extent when the connector is coupled and uncoupled under load.

32 Claims, 25 Drawing Figures HAY 2 8 I974 SHEEI 1 OF 5 on NW INVENTOR. JOSEPH D. KlNNEAR ATTOQNF'YS PATENTEDMY28 W I 38l 3;638

SHEET 3 UF 5 INVENTOR. JOSEPH D. KINNEAR FIG. I!

ATTORNEYS I CABLE CONNECTOR This application is a continuation-in-part of my prior co-pending application Ser. No. 57,568, filed July 23, I970, now abandoned.

This invention relates to electrical connectors and more particularly to a device for releasably coupling or connecting electric power cables and the like.

The connector of this invention is usable for releasably connecting electric cables to each other and to control or other electric panels, and is particularly suitable for releasably connecting cables adapted to carry rather low voltage, high current loads in the range of 200 to several thousand amperes. Such cables areusually used to carry a direct current although the coupler of this invention is suitable for use with both alternating and direct current sources. This coupler is particularly useful on battery-operated electric industrial lifttrucks, heavy duty welders and other electrical devices with high current loads requiring a disconnect from their electrical power source.

Objects of this invention are to provide a coupling device for heavy current loads which can be readily connected and disconnected, which has a dead front providing improved safety characteristics such that the electrical conductors cannot be accidentally touched, in which a male or female conductor cannot be coupled with a conductor carrying a current at another or opposite potential (thereby preventing accidental coupling of cables to improper power sources), which inhibits the tendency to are and burn the conductors when connected and disconnected under load without diminishing the load carrying capacity (thereby decreasing the safety hazard to persons manipulating the connector and substantially increasing its useful life), and to provide a compact connector of economical construction and assembly which can be easily serviced and maintained.

These and other objects, features and advantages of this invention will be apparent from the following description and accompanying drawings. in which:

FIG. 1 is a plan view of a double pole connector embodying this invention shown in the coupled condition.

FIG. 2 is a sectional view on line 22 of FIG. I illustrating the connector in the uncoupled or disconnected condition.

FIGS. 3 and 4 are end views of the confronting faces of the two housings of the connector.

FIG. 5 is a fragmentary semi-schematic view of the means employed for assuring connection to the proper power source.

FIG. 6 is a fragmentary side elevational view with a cut away section on line 66 of FIG. 1 illustrating a latch mechanism for releasably securing the two housings of the connector in coupled condition.

FIG. 7 is a fragmentary side elevational view with a cut away section on line 7 -7 of FIG. I illustrating the component parts of the conductor receptacles and plugs and the housings in coupled condition.

FIGS. 8A and 8B are end and side elevational views respectively of a spacer ring in the tulip connector assembly.

FIG. 9 is an isometric view of a petal of the tulip connector assembly.

FIG. 10 is a sectional view on line 10-10 of FIG. 7.

FIG. 11 is a fragmentary sectional view similar to the sectional portion of FIG. 7 illustrating a modified form of tulip assembly.

FIG. 12 is an end view of a carrier for the conductors of the connector device.

FIG. I3 is a sectional view somewhat similar to FIG. 6 but showing a modified form of latch assembly for retaining the two housings in locked conductorconnecting condition.

FIG. 14 is a perspective view of the spring latch shown in FIG. I3.

FIG. 15 is a side view, partly in section, of a cable connector housing showing a further modified form of latch.

FIG. I6 is a perspective view of the spring latch shown in FIG. 15.

FIG. 17 is a longitudinal sectional view, with parts broken away, showing a single pole connector according to the present invention of modified construction.

FIG. 18 is a fragmentary view of one of the tubular connectors shown in FIG. 17.

FIG. 19 is an end view of the conductor shown in FIG. 18.

FIG. 20 is a fragmentary side elevational view of the pilot pin on the other conductor illustrated in FIG. 17.

FIG. 21 is an end view of the component shown at the left of the assembly illustrated in FIG. 17.

FIG. 22 shows a modified form of tubular conductor somewhat similar to that illustrated in FIG. 19.

FIGS. 23 and 24 show a modified form of tulip connector and the manner in which it is engaged with one of the tubular conductors.

As shown in FIGS. 1 and 2, a connector device 20 embodying the invention includes housings 22 and 24, each attached to a pair of cables 26 and 28 respectively. Both housings include hollow outer boots 30 and 32 of a resilient supple nonconductive material, such as rubber, in which rigid bodies or shells 34 and 36 of a nonconductive material are slidably received. The front end portion of housing 22 is slidably received in an opposed front end pocket or socket of housing 24. Socket 35 is defined in part by a continuous integral peripheral wall 37 providing a generally airtight seal between the coupled housings. Identical rigid carriers 38 (specifically shown in FIG. 12) of a nonconductive material mount two pair of axially aligned tubular conductors or contacts 40 and 42 in boots 30 and 32. Insulated cables 26 and 28 are received in tubular necks 44 of boots 30 and 32 and are mechanically and electrically connected to contacts 40 and 42 by crimps or indentations 46. Cables 26,28 are mechanically secured and sealed airtightly to boots 30 and 32 by hose-type clamps 48 encircling necks 44.

As shown in FIGS. 2, 3, 4, 6 and 7, the rear or inner end portions 49 of shells 34 and 36 are generally hollow with an outer sidewall 50. The front of outer ends of shells 34,36 are defined by an end wall 52. A pair of laterally spaced cylindrical recesses 53 extend between end wall 52 and the hollow portion 49 at the rear of each shell. Carriers 38 are slidably received in the hollow portions 49 of shells 34,36. Conductor contacts 40,42 are mounted in the shells by D-rings 56. As

shown in FIG. 12, each carrier 38 has two D-shaped recesses 55 to receive and retain D-rings 56 which are fixed to conductors 40 and 42 by pins 57 (FIG. 2).

Shells 34,36 and their carriers 38 are fixed with respect to each other and secured in boots 30,32 by bolt and nut assemblies 59 (FIG. 6). Thus, the tubular conductors 40,42 are prevented from rotating relative to boots 30,32.

As shown in FIGS. 2 and 3, a radially resilient conductive connector sleeve in the form of a tulip connector assembly, designated generally as 58, engages the outer cylindrical surface at the free end of each conductor contact 40 and each is received in one of the cylindrical recesses 53 of shell 34. Access holes 54 in end wall 52 of shell 34 are concentric with each tubular contact 40, and the free end of tulip connector 58 engages a ridge or rim 60 on the inside of wall 52 around each hole 54 to retain the tulip connectors 58 concentric with holes 54. A guide pin 62 of an electrically nonconductive material such as nylon is received within each tubular contact 40. Each guide pin is fixed against axial and rotative movement within its tubular conductor. Each guide pin 62 extends coaxially into a hole 54 in wall 52 of shell 34 and terminates at its forward end essentially flush with the front face of shell 34. The extension of pins 62 into holes 54 totally encloses contacts 40 and tulip connectors 58 in housing 22 except for two very narrow ring-like openings 63 (FIG. 2) formed between the pins and the edges of the holes which provide a dead front for housing 22. This dead front eliminates the risk of a person accidentally contacting contacts 40, thereby reducing the hazard of electrical shock and injury to persons using connector 20. For example, if cables 26,28 are of 4/0 size, contacts 40 would have a diameter of about inches. However, the wall thickness of conductor 42 would be on the order of l/l6 inches and the width of annular openings 63 would be on the order of 3/32 inches. This relatively narrow opening coupled with its circular contour precludes accidental or otherwise insertion of a persons finger or a tool (such as a screwdriver) into openings 63 into contact with petals 112 of the tulip connector. Each tulip 58 is prevented from shifting axially in its pocket 53 beyond a very slight extent by abutment with end wall 52 and D-ring 56.

As shown in FIGS. 2 and 4, the two tubular contacts 42 associated with housing 24 are axially received in recesses 53 by tubular guides 68 which are formed as integral rearward extensions on wall 52 of shell 36. Contacts 40 are prevented from shifting axially by abutment of D-rings 56 with guides 68 and carrier 38. The free end of each contact 42 extends forwardly beyond shell 36 and into pocket 35 to provide a tubular male plug engageable in the female receptacle formed by each tulip 58, guide pin 62, and contact 40. A key 76 extends axially in each contact 42 and is fixed therein by a pin 78. When the housings are coupled (as shown in FIG. 7) each tubular plug portion of conductor 42 is received on guide pin 62 and extends through opening 54 and engages the free end of tulip assembly 58. Key 76 is received in a properly radially oriented axially extending slot 86 in guide pin 62. As shown in FIG. 5, contacts 40,42 can be rotatably oriented relative to D-rings 56 so that their slots 86 and keys 76 assume different angular positions which are related to the particular voltage of the cables with which the connector device is used. The different angular orientation of slots 86 and keys 76 for each voltage prevents a housing of one cable from being coupled with a mating housing of another cable at a different voltage'which avoids connecting a load with a source of power at an incorrect voltage. The angular position of keys 76 and slots 86 is fixed by the angular position in which D-rings 56 are secured to contacts 40 and 42 since the D-rings are restrained from rotation by the correspondingly shaped recesses 55 in carriers 38. By using D-rings 56 to retain slot 86 and key 76 in any predetermined angular position, the assemblies of contact 40 and pin 62 and assemblies of contact 42 and key 76 can be identical regardless of the eventually desired position of angular orientation.

As shown in FIG. 6, housings 22,24 can be releasably retained in the coupled position by a latch pin assembly. A latch pin 92 with a groove 94 adjacent its leading end, a reduced shank portion 96 adjacent the other end, and an intermediate shoulder 98 is retained in a pocket 100 in shell 36 with its free leading end projecting forwardly through an opening 101 in wall 52 of shell 36. A plunger 102 is slidably retained in a pocket 106 in shell 34 by a screw 108 and is biased upwardly by a spring 110. Plunger 102 is formed with cavity 111 axially aligned with the. forward end of pin 92. When housings 22,24 are telescopically engaged pin 92 is adapted to project into pocket 106 and groove 94 is en gaged by a ring 104 on plugner 102 which is depressed by the tapered end of pin 92 to releasably latch the housings together.

Tulip connector 58, as shown in FIGS. 2, 7 and 10, has a plurality of conductive metal petals 112 of identical shape and size arranged in a generally parallel edge abutting spatial circular or tube-like shape. Petals 112 are urged radially inward into edge abutting relationship by a pair of garter springs 114 bearing on their outer periphery adjacent their free ends. One end of each garter spring is threaded within its other end (as shown in FIG. 10) so that the spring will exert a sub stantially equal radially inward force on each petal 1 12. A spacer ring 116 is centrally received within petals 112 in a plane generally perpendicular to the longitudinal axis of the tulip connector to stabilize the assembly of petals 112 so that it will not be readily collapsed by a radially inward force applied locally on the outer periphery of the petals 112. As shown in FIG. 8 spacer ring 116 is wound from a generally flat strip of metal with a rectangular cross section and has as shown in FIGS. 8A and 88 an offset central portion 118 with the free ends 120 of the metal strip terminating adjacent the offset on opposite sides thereof so that the ring has a substantially uniform thickness throughout its periphery. Each petal 112 has in the central portion on the interior side a generally transverse groove 122 adapted to engage in assembly with the sidewalls of spacer ring 116. Engagement of spacer ring 116 in grooves 122 aligns petals 112 so that they extend longitudinally generally parallel to each other and restrains the petals from being longitudinally displaced with respect to each other so that their opposite ends will remain circumferentially aligned and terminate in substantially a single plane perpendicular to the longitudinal axis of the tulip connector.

Petals 112 are formed with a generally sinuous longitudinal cross section defined by a central outwardly curved portion 124 and reverse curved portions 126 adjacent their free ends adapted to provide annular seats for springs 114. As shown in FIG. 10, the radially inner surface of end portions 126 has a radius of curvature as at 128 in a plane perpendicular to the longitudinal axis of petal 112 smaller than the outer radius of tubular contacts 40,42. The smaller radius of curved surface 128 provides each petal with two points or surfaces of contact 130 adjacent each end thereof for engagement with contacts 40,42. Providing each petal with two distinct points of contact 130 with each contact 40,42 reduces the tendency and severity of arcing when connector 20 is coupled and uncoupled under load because it provides a plurality of electrically conductive paths on each petal 112. The smaller radius of the petals also enables the number of petals used in the tulip to be increased to accomodate larger size conductors. The tendency and severity of arcing is also decreased by the use of guide pin 62 and opening 54 in shell 34 to axially align the male tubular plug of contact 42 so that it engages and disengages all of the petals 112 of tulip assembly 58 at substantially the same time.

The use of rim or ridge 60 adjacent the inner side of opening 54 to align the free end of all of petals 112 of tulip assembly 58 so that they are coaxial with opening 54 and pin 62 also decreases the tendency and severity of arcing when connector 22 is coupled under load.

The tendency for arcing is also reduced by the fact that when the connector is coupled or uncoupled the opposite ends of the tulip petals abut and are aligned in the same vertical plane .perpendicular to the longitudinal axis of the tulip connector by the inner face of wall 52 and D-ring 56.

When housings 22,24 are coupled, flexible wall 37 provides a substantially airtight seal enclosing the conductors in boots 30,32 so that a partial vacuum is created within the enclosure by separation ofthemale and female housings. This partial vacuum also decreases the tendency and severity of arcing when connector 20 is uncoupled under load.

A slightly modified form of a tulip connector designated generally as 132 is shown in FIG. 11. Tulip assembly 132 has petals 112, a spacer ring 116 and garter springs 114 identical to tulip connector 58. To further stabilize petals 112.50 that they cannot be easily collapsed by an application of radially inward force on one end ofthe petals. retainer rings 134 are inserted in garter springs 114. Retainer rings 134 have substantially the same form as spacer ring 116 with an offset center portion and free ends terminating adjacent the offset portion on opposite sides thereof. When a radially inward force is applied to one end of a petal 112, the retainer ring 134 adjacent the opposite end of the petal prevents the petal from excessive pivoting about spacer ring 116 and disengaging from edge abutting relationship with its adjacent petals. If a petal is disengaged from edge abutting relationship with its adjacent petals, the tulip connector will usually collapse. Thus, retainer rings 134 tend to stabilize tulip connector 132 when one or both ends are disengaged from contacts 40,42.

In using the connector device 20 to couple or electrically connect two pair of cables 26,28, housing 22 is slidably inserted fully into pocket 82 of housing 24. As housing 22is inserted into housing 24 pilot and guide pins 62 engage in the free ends of tubular'contacts 42 and coaxially align the contacts with the free ends of tulip connectors 58. As pointed out, this decreases the tendency and severity of arcing if conductors 40,42 are electrically connected and disconnected under load. Further engagement of housing 22 in housing 24 causes the free end of the petals 1 12 of tulip connectors 58 to engage the outer cylindrical surface of contacts 42, thereby electrically connecting each contact 42 with its corresponding contact 40. Preferably, the petals 112 of each tulip connector have two points of engagement or contact at each end with contacts 40,42 which tends to increase the current carrying capacity of connector device 20 and to decrease the tendency of arcing and the severity of arcing if contacts 40,42 are electrically connected and disconnected under load. As housing 22 becomes fully engaged in housing 24 the free end of latch pin 92 engages ring 104 moving plunger 102 initially downward (FIG. 6) and then allowing plunger 102 to snap upward as the bottom portion of ring 104 engages in groove 94 to lock housings 22,24 together in the fully coupled position.

To disengage housings 22 and 24 and electrically disconnect conductors 40 and 42, plunger 102 is manually pushed downward against the bias of its spring by applying pressure in the direction of the arrow in FIG. 6 on the portion of flexible wall 84 above plunger 102 to disengage ring 104 from latch pin 92 so that the housings can be manually separated. As the housings are separated the free end of each contact 42 slidably disengages from all of the petals 112 of its corresponding tulip connector 58 simultaneously, thereby electri cally disconnecting contacts 40,42. Withdrawal of each contact 42 from its associated tulip assembly 58 allows the free end of the tulip to engage with ridge 60 so that it will be coaxially aligned withits associated guide pin 62 and hole 54, thereby decreasing the tendency and severity of arcing if contacts 40,42 are subsequently coupled under load. Separation of housings 22 and 24 also creates a partial vacuum reducing the tendency and severity of arcing if contacts 40,42 are electrically disconnected under load.

It will be understood that in the arrangement illustrated cables 26 would be electrically connected to a power source and cables 28 would be connected to the load to be supplied with power.

The embodiment illustrated in FIG. 13 is in general similar to the overall arrangement illustrated in H6. 6. The general design of housing 22a and the internal components thereof follow closely the general design of housing 22 and the components thereof. Likewise, the general design and the internal components of housing 24a follow closely the general design of housing 24 and the internal components thereof. However, in the modified construction shown in FlG. 13 the latch assembly for retaining the two housings in the locked condition comprises a stud which extends through the front wall 52a of shell 36a and is provided with a tapered free end 152 and an annular groove 154 which is flush with the inner face of the front wall of pocket 106a. Stud 150 is retained in housing 24a by a snap ring 156 and a screw 158.

Within pocket 1060 there is arranged a spring latch 160 having resilient ears 162,164 projecting downwardly into pocket 106a and connected by a resilient bight portion 166 formed with a handle extension 168. As shown in FIG. 14, resilient ears 162,164 depend from bight portion 166 in a somewhat divergent manner so that the lower pointed ends of these spring ears must be squeezed together in order to insert them in pocket 106a. The peripheral wall 37a of housing 24a is cut away as at 170 and the top wall of pocket 106a is correspondingly slotted to accommodate latch 160. When spring ears 162,164 are inserted in pocket 106a latch 160 is locked in place by a screw 172 which threads through an opening 174 in spring ear 162. In this free relaxed position ofthe spring latch the opening 176 in spring ear 164 is offset downwardly from the end 152 of pin 150 and handle 168 simply overlies the outer portion of housing 22a in somewhat spaced relation thereto. However, it is prevented from being accidentally depressed by a pair of upstanding ribs 178 on housing 22a which straddle the opposite side edges of handle 168. When it is desired to release the two hous ings, handle 168 is depressed to resiliently urge spring ear 164 upwardly to a position wherein the upper edge of opening 176 in ear 164 is retracted from annular groove 154 and opening 176 is shifted upwardly to a position where it is concentric with and capable of enabling pin 150 to be retracted therefrom. When the two housings are in the separated condition the tapered end 152 engages the offset upper edge of opening 176 to resiliently displace ear 164 upwardly and when the housings are fully telescoped together the upper edge of opening 176 snaps into engagement with annular groove 154 to retain the housings in the locked condition.

In the arrangement illustrated in FIG. 13 an additional conductor 180 is assembled within and projects from housing 240. Adjacent the front face 52a of shell 36a conductor 180 has a spring-biased plunger 182 which is depressed to a circuit closing position when the two housings are locked together.

The modification shown in FIG. 15 differs from that shown in FIG. 13 primarily in that the spring latch 184 is merely U-shapcd having a pair of resilient ears 186 and 188 which are connected by a bight portion 190 and which in the free position depend from bight portion 190 in a slightly divergent direction. When ears 186,188 are slightly compressed latch 184 is adapted to be inserted in pocket 106a and retained therein by screw I72 which threads into an opening 192 in spring car 186. It will be observed that in the normal free position of latch I84 bight portion 190 is biased so that it extends upwardly from ear 186 to car 188 and that the opening 194 in spring ear 188 is offset axially upwardly from opening 196 in the front wall of shell 340 which is adapted to accommodate pin-150. Thus, to interlock the two housings they are telescoped together to a position wherein the tapered end 152 of pin 150 urges the lower edge of opening 194 downwardly to displace ear 188 downwardly so that the opening therein registers with pin 150. As soon as ear 188 registers axially with slot 154 in pin 150 the spring bias of latch 184 displaces ear 188 upwardly to interengage the lower edge of opening 194 with annular groove 154 and thus lock the two housings together. Obviously once locked the two housings can be separated by merely depressing on the forward portion of the bight portion 190 of latch 184 to shift ear 188 downwardly to a position wherein opening 194 is coaxially aligned with pin 150.

In the previous embodiments illustrated the cale connectors were of the dual pole type; namely, connectors for electrically connecting two conductors of opposite polarity in one housing with two other conductors of opposite polarity in the other housing. In FIG. 17 there is illustrated a single pole conductor; namely, a conductor for simply electrically connecting two conductors of the same polarity. Thus, there is illustrated a cable 200 having a tubular conductor 202 crimped or otherwise secured to the bared end thereof and a second cable 204 having a tubular conductor 206 crimped or otherwise connected to the bared end thereof. As in the previous embodiment the connector illustrated in FIG. 17 includes a radially resilient conductive connector sleeve in the form of a tulip connector generally designated 208. Tulip connector 208 is similar in most respects to the tulip connector previously described in that it includes a plurality of conductive metal petals 210 of identical shape and size arranged in generally parallel edge abutting spatial circular or tubular shape. Petals 210 are urged radially inwardly into edge abutting relationship by a pair of garter springs 212. Each petal 210 has a centrally outwardly bowed portion 214 (FIG. 23) with reversely bent end portions 216 in which the garter springs 212 are seated. Tulip connector 203 is mounted on the leading end of tubular conductor 202 by flaring the leading open end of conductor 202 outwardly as indicated at 218 in FIGS. 23 and 24. The flared end 218 of conductor 202 generally serves the same function as spacer ring 116 shown, for example, in FIG. 2. In addition, it automatically provides yieldable connection between the tulip connector and conductor 202.

A nonconductive pilot pin 220 is press fitted or otherwise fixed into the open leading end of conductor 202. As shown in FIG. 17, pin 220 extends axially beyond the flared end 218 of conductor 202 and terminates at its slightly tapered leading end designated 222. In the arrangement illustrated in FIGS. 17 through 21, pilot pin 220 has a pair of diametrically opposite axially extending grooves 224 on the outer surface thereof. Grooves 224 extend axially inwardly from the leading end 222 of pilot pin 220 and at the axially inner end these grooves have circumferential extensions 226.

The other conductor 206 has a pair of diametrically opposite inwardly extending lugs 228 which are dimensioned to be snugly received in grooves 224 in pilot pin 220. When conductor 206 is telescoped into engagement with tulip connector 208 to a position wherein lugs 228 advance to the inner ends of grooves 224, the leading end of conductor 206 is firmly engaged with the petals of tulip connector 208 and the two conductors can be relatively rotated in opposite directions to interengage lugs 228 with the circumferential extension 226 of grooves 224. This effectively couples cables 200 and 204 together and prevents accidental disconnection thereof. It also prevents interconnection of two cables of different polarities where the lugs 228 and slots 224 would be so designed as to prevent their interengagement.

The arrangement illustrated in FIG. 17 incorporates several features which tend to minimize arcing when the conductors are connected and disconnected. One of these features has to do with the provision of an insulating sheath 230 formed of rubber or other suitable material which is molded or otherwise applied to cable 200 so as to enclose conductor 202 and tulip connector 208. It will be noted that the enlarged portion 232 of sheath 230 extends well beyond tulip connector 208 and terminates just short of the leading end 222 of pilot pin 220. The forward end of sheath 230 is formed with a circular opening 234 provided with a thin tapered and deflectable lip 236. The other cable 204 is enclosed with a cylindrical sheath 238 which terminates short of the leading end of conductor 206 as illustrated in FIG. 17. The outer diameter of sheath 238 and the diameter of opening 234 as defined by lip 236 is such that when the two cables are connected as shown in FIG. 17. the chamber formed by the enlarged portion 232 of sheath 230 is substantially airtight. Thus, when the cables are disconnected, separation of the two conductors 202,206 creates a partial vacuum in the chamber formed by the enlargement 232 on sheath 230 which tends to minimize arcing between the conductor 206 and the petals 210 of tulip connector 208. In addition, as more specifically shown in FIGS. 23 and 24, the outwardly bowed portion 214 of each petal 210 is substantially thicker than the reversely bent portions 216 of these petals. Furthermore. the outer surface of these petals forms a smooth continuous curve whereas the radially inner surfaces of these petals define curves which have a rather abrupt intersection as at 240. Thus, the opposite end portions of each petal between intersections 240 and the free ends of the petal are not only thinner than the remaining central portion but also de fine a circle of slightly greater inner diameter than the curved portions 242 of minimum inner diameter of the tulip connectors. The advantage of this construction is shown in FIG. 23 where it can be seen that as soon as the leading end of conductor 206 comes into engagement with the corresponding end of tulip connector 208 it engages the thinner reversely bent portions 216 of each petal. If any arcing occurs it occurs at this instant where initial contact is made between conductor 206 and the petals of the tulip connector. However, if the conductor is advanced into the tulip connector after initial contact is made, it engages with the thickened curved portions 242 of the petals and there is a slight clearance indicated at 244 in FIG. 24 between the conductor and the thinner end portions 216. Thus, the current is conducted from conductor 206 to con ductor 202 through the thicker, and therefore greater, current carrying capacity central portions of the petals. Likewise, when the two housings are separated the two conductors retract from one another from the position shown in FIG. 24 to that shown in FIGS. 23. Conductor 206 remains in contact with each petal 210 until contact is broken with the thinned end portion 216 of each petal. Accordingly, if arcing occurs it occurs between the conductor and the thinned end portion. Thus. while a certain amount of arcing may be inevitable when the conductors are connected and disconnected under heavy loads, nevertheless the portions of the petals and of the conductors which are subject to arcing are not operative for conducting current when the two conductors are fully connected.

In the event that an arrangement such as shown in FIG. 17 is utilized for interconnecting two sets of cables of different polarity it is important that the two negative cables be properly connected and the two positive cables be properly connected. Under such circumstances one set of conductors would have the lug and groove arrangement shown in FIGS. 18 thru 21 and the other two cables would have the lug and groove arrangement shown in FIG. 22. In the latter arrangement two diametrically opposed lugs 246 would be wider than the other two diametrically opposed lugs 248. Likewise, the four grooves in the pilot pin of the other conductor would be similarly arranged and dimensioned so that lugs 246 could only interfit with the two wider grooves (similar to grooves 224 in FIG. 20). This would prevent interconnection of a cable of positive polarity with another cable of negative polarity.

I claim:

1. An electrical connector comprising first and second conductors each having an axially extending cylindrical exterior surface, a resilient connector sleeve electrically connected on one end of the first conductor, said connector sleeve comprising a plurality of axially extending conductive petals arranged in generally circular spatial relation and biased radially inward, each of said petals adjacent one end thereof being adapted to be telescoped over a frictionally engaged with said cylindrical surface of the second conductor. a pilot pin of nonconductive material extending axially from and beyond the leading end of oneof said conductors and a coaxial socket at the leading end of the other conductor, said socket being adapted to slideably receive said pin for coaxially aligning said cylindrical surface of the second conductor with said petals of said connector sleeve prior to and during axial movement of said cylindrical surface of said second conductor into telescopic engagement with said petals of said connector sleeve.

2. The electrical connector of claim I in which each of said petals has two points of contact adjacent each end thereof with said cylindrical surface of said conductors.

3. The electrical connector of claim 1 which also comprises a key mounted in a radially extending predetermined angular orientation in said socket and a slot in a corresponding angular orientation in said pin to slidably receive said key.

4. The electrical connector of claim I wherein the petals of said connector sleeve resiliently engage the outer cylindrical surface of said end of said first conductor, said petals being biased radially inwardly by springs which encircle the petals and cause the axially extending edges thereof to abut.

5. The electrical connector of claim 4 in which said springs comprise garter springs circumscribing said pet als and bearing on the outer side thereof adjacent opposite ends of said petals, and including a rigid retainer ring mounted within each of said garter springs adjacent opposite ends of said petals to limit the extent to which the ends of said petals can be moved radially to prevent disengagement of the side edges of a petal with the side edges of its adjacent petals.

6. The electrical connector of claim I wherein said pin extends axially beyond the leading end of the conductor on which it is mounted and said socket is located at the leading end of the other conductor, said pin telescopingly engaging said socket prior to telescopic interengagement of said sleeve and said second conductor.

7. The electrical connector of claim 6 wherein said conductors comprise two pairs, one conductor in each pair being of opposite polarity from the other conductor in said pair, said pin extending axially from each conductor of one pair, said pins having axially extending grooves on the surface thereof and each conductor of the other pair having radially inwardly extending lugs at the leading ends thereof, the grooves and lugs of one set being of different arrangement than the grooves and lugs of the other set such that in each pair of conductors a conductor of one polarity can be telescopically engaged only with the sleeve on the conductor of similar polarity of the other pair.

8. The electrical connector of claim 6 wherein said pin has an axially extending groove thereon and said other conductor has a radially inwardly prjecting lug at the leading end thereof which must register axially with said groove to enable telescopic engagement of said second conductor and said sleeve.

9. The electrical connector of claim 8 wherein the axially inner end of said groove has a circumferential extension adapted to receive said lug when the lug registers axially with said extension and one of said conductors is rotated about its axis relative to the other conductor.

10. The electrical connector of claim 9 wherein said circumferential extension is located to register with said lug after said sleeve and the second conductor have telescopically interengaged.

11. The electrical connector of claim 1 which also comprises first and second housings of nonconductive material which define chambers for said conductors which are generally closed,except at the confronting end faces of said housings, said first housing having a socket opening to the exterior thereof and adapted to telescopically receive a portion of said second housing, said housing socket being dimensioned to have a close fit with said portion of the second housing, one of said housings surrounding said first conductor and the other housing surrounding the second conductor such that when the second housing is fully received in the socket of the first housing the second conductor telescopically engages said petals of said connector sleeve, said housing socket being dimensioned to have a close fit with said portion of said second housing such that when the housings are telescopically disengaged a partial vacuum is created within the housings at the portions thereof enclosing the connected portions of said conductors, the axial extent of said housing socket being dimensioned such that when the housings are telescopically disengaged the petals of said connector sleeve disengage said second other conductor prior to disengagement of said housing socket and said second housing.

12. The electrical connector of claim 11 which also comprises a wall of a nonconductive material on said housing enclosing said one conductor, said wall being adjacent said end of said petals of said connector sleeve and having a hole therein substantially coaxial with said end of said petals, said pilot pin being carried by said first conductor and extending axially beyond the end thereof and beyond said end of said petals of said connector sleeve, said pilot pin extending coaxially with said hole in said wall, and in which said second conductor has a tubular leading end portion having an outer diameter only slightly smaller than said hole and an inner diameter only slightly greater thansaid pilot pin, said leading end portion of said second conductor being adapted to extend through said hole, telescope over said pilot pin and engage said end of said petals when said housings are fully telescopically engaged.

13. The electrical connector of claim 12 wherein said pin extends concentrically into said hole to define an annular opening in said wall for guiding the tubular leading end portion of said second conductor into concentric engagement withthe petals of the connector sleeve.

14,. The electrical connector of claim 12 including means on the inner side of said wall surrounding said hole and supporting said ends of said petals concentrically with said hole.

15. The electrical'connector of claim 1 which includes first and second housings of a nonconductive material surrounding said conductors, a single conductor in each of said housings, one of said housings snugly embracing said first conductor and being circumferentially enlarged to accommodate said sleeve and extending axially beyond said sleeve, said enlarged portion of said one housing having an opening at the free end thereof concentric with the axis of the sleeve therein. the other housing snugly embracing said second conductor, the opening in the end of the first housing being dimensioned to snugly receive the portion of the second conductor surrounded by said second housing so that when said second conductor is engaged with said sleeve the opening in the first housing forms a generally air-tight fit with the outer surface portion of the second housing.

16. The electrical connector of claim 15 wherein the opening in the first housing has a peripheral, generally radially inwardly extending flexible lip thereon dimensioned to facilitate formation of said generally air-tight fitting with the surface of the first housing.

17. The electrical connector of claim 12 which also comprises a key mounted in a radially extending predetermined angular orientation in said tubular portion of said second conductor and in which said pin has a slot in a corresponding angular orientation to slidably receive said key. I

18. The electrical connector of claim 17 wherein said nonconductive pin extends coaxially beyond the free end of the first housing to at least the open end thereof, said second conductor being tubular at the free end thereof so that said pin telescopes within said second conductor with a smooth guiding fit as the two housings are interengaged before the free end of the second con ductor is engaged by the leading ends of the petals of said sleeve.

19. The electrical connector of claim 18 wherein said pin has an axially extending groove therein and said second conductor has a radially inwardly extending lug at the free end thereof which must axially align and reg ister with said groove to enable telescopic engagement of said pin and second conductor, the groove and lug arrangement being different for conductors of different voltages and polarities so that only conductors of similar voltages and polarities can be telescopically engaged.

20. The electrical connector of claim 1 wherein said sleeve connector comprises a tulip connector, each of said petals having a radially outwardly bowed central portion with reversely bent end portions of smaller outer diameter, said end portions having radially outwardly curved ends, the centrally bowed portion of each petal having a greater radial thickness than the reversely bent end portions, the minimum inner diameter of the centrally bowed portion being smaller than the minimum inner diameter of the reversely bent end portions so that, when said second conductor is telescopically engaged with said tulip connector, the outer surface of said second conductor first encounters the inner periphery of the reversely bent end portions and, as the second conductor is further telescoped into said sleeve, the end portion of the second conductor then contacts the inner periphery of the centrally bowed portion.

21. The electrical connector of claim 20 wherein said inner diameters of said centrally bowed portions are dimensioned such that, when said second conductor is fully telecoped within said sleeve, the reversely bent end portions are radially spaced outwardly from the outer peripheral surface of said second conductor.

22. An electrical connector comprising a pair of housings each surrounding an end of a conductor, said conductor ends being of tubular shape, one of said conductors having a nonconductive pilot pin extending coaxially beyond the end thereof, a resilient connector sleeve on the end of said one conductor and having one end thereof extending circumferentially around said pilot pin, the housing enclosing said one conductor having an end wall provided with an opening aligned axially with said pin and slightly larger in diameter than said pin, said pin extending into said opening and terminating substantially flush with the outer face of said end wall to define a narrow annular opening in said end wall, said connector sleeve being disposed behind said wall so that said wall and said pin define a dead front on said housing, the end of the other conductor being tubular and adapted to be inserted through said annular opening between the outer end of said pin and opening in said end wall to engage with said end of the resilient connector sleeve.

23. The electrical connector of claim 22 including means on the inner side of said wall surrounding said opening and supporting said end of the resilient connector sleeve concentric with the opening.

24. The electrical connector of claim 22 wherein said connector sleeve comprises a series of petals of arcuate shape in transverse section, said petals being arranged in circumferential fashion with their longitudinal edges in abutting relation, yielding means circumferentially circumscribing said end of said connector sleeve, the opening defined by said end of the connector sleeve being smaller than the outer diameter of the end of said other conductor.

25. The electrical connector of claim 22 wherein said connector sleeve comprises a series of petals of arcuate shape in transverse section, said petals being arranged in circumferential fashion with their longitudinal edges in abutting relation, yielding means circumferentially circumsribing said end of said connector sleeve, said end wall being perpendicular to the longitudinal axis of the connector sleeve at the portion of its inner face surrounding said opening, means in said one housing adjacent the other end of said connector sleeve forming an abutment perpendicular to the longitudinal axis of said connector sleeve, said petals all being the same length and slightly shorter than the distance between said abutment and said portion of said end wall.

26. The electrical connector of claim 22 wherein the width of said annular space is not more than about 3/32 inches.

27. The electrical connector of claim 26 wherein said other conductor has a diameter of at least about inches.

28. A tulip connector for electrically coupling a pair of conductors comprising, a plurality of axially extendi4 ing conductive petals arranged in generally circular spatial relation and biased radially inwardly to define a generally circular passageway in the connector, one end of said connector being adapted to be telescoped over and frictionally engage the outer cylindrical surface of a conductor having a diameter at least slightly greater than the minimum diameter of the passageway in the connector, each of said petals having a radially outwardly bowed central portion with a reversely bent. radially outwardly extending portion at said one end of the connector, spring means seated within and extending circumferentially around the annular seat formed by the junction of said outwardly bowed portion and said reversely bent end portions of said petals, said reversely bent end portions being thinner than the portion of the outwardly bowed portion of the petal spaced axially inwardly of said junction, the radially inner surfaces of the outwardly bowed portions being curved radially outwardly to intersect with the radially inner surfaces of said reversely bent end portions at said junction so that the minimum inner diameter of the outwardly bowed portions is smaller than the inner diameter of said junction, the diameter of the portion of the passageway defined by the radially inner surfaces of the reversely bent end portions being substantially greater at the free ends of said end portions than at said junc-' tion so that, when said conductor with said cylindrical outer surface is telescopically engaged with said one end of the connector, the outer surface of the conductor first encounters the inner periphery of the reversely bent end portions and, as the conductor is further telescoped into said connector, the leading end of the con- ,ductor thereafter contacts the inner periphery of the connector at said portion of the passageway of minimum diameter which is spaced axially inwardly of said junction and causes the connector to circumferentially enlarge to thereby displace the radially inner surfaces of said petals at said junction radially outwardly from the outer surface of the conductor.

29. A tulip connector as called for in claim 28 wherein the configuration of the other end of each petal is substantially the same as said one end.

30. A tulip connector as called for in claim 28 wherein the inner surfaces of the outwardly bowed portion and the reversely bent end portion of each petal are shaped to form a sharp line of intersection at said junction.

31. A tulip connector as called for in claim 28 wherein the inner surface of each petal at said junction is defined by the line of intersection between oppositely inclined surfaces.

32. A tulip connector as called for in claim 28 wherein the inner surface of each petal at said junction is defined by the intersection between surfaces which are inclined relative to one another in a direction axially of said passageway.

9' I I UNITED STATES PATENT OFFICE z CERTITTCATE OF CORRECTIGN Patent NO. 3a8l3638 D t d May 28, 1974- Inventofls) KINNEAR, Joseph D.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 10., Line 23 fiance surface and insert in place thereof surfaces Column 11, ,Line'36 Cancel "other" Correct Patentee's Address on Title Page to read:

Warren, Michigan Signed and sealed this 15th day of October 197-4 (SEAL) Attest:

! McCOY M. GZBSON JR. (3.. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. An electrical connector comprising first and second conductors each having an axially extending cylindrical exterior surface, a resilient connector sleeve electrically connected on one end of the first conductor, said connector sleeve comprising a plurality of axially extending conductive petals arranged in generally circular spatial relation and biased radially inward, each of said petals adjacent one end thereof being adapted to be telescoped over a frictionally engaged with said cylindrical surface of the second conductor, a pilot pin of nonconductive material extending axially from and beyond the leading end of one of said conductors and a co-axial socket at the leading end of the other conductor, said socket being adapted to slideably receive said pin for coaxially aligning said cylindrical surface of the second conductor with said petals of said connector sleeve prior to and during axial movement of said cylindrical surface of said second conductor into telescopic engagement with said petals of said connector sleeve.
 2. The electrical connector of claim 1 in which each of said petals has two points of contact adjacent each end thereof with said cylindrical surface of said conductors.
 3. The electrical connector of claim 1 which also comprises a key mounted in a radially extending predetermined angular orientation in said socket and a slot in a corresponding angular orientation in said pin to slidably receive said key.
 4. The electrical connector of claim 1 wherein the petals of said connector sleeve resiliently engage the outer cylindrical surface of said end of said first conductor, said petals being biased radially inwardly by springs which encircle the petals and cause the axially extending edges thereof to abut.
 5. The electrical connector of claim 4 in which said springs comprise garter springs circumscribing said petals and bearing on the outer side thereof adjacent opposite ends of said petals, and including a rigid retainer ring mounted within each of said garter springs adjacent opposite ends of said petals to limit the extent to which the ends of said petals can be moved radially to prevent disengagement of the side edges of a petal with the side edges of its adjacent petals.
 6. The electrical connector of claim 1 wherein said pin extends axially beyond the leading end of the conductor on which it is mounted and said socket is located at the leading end of the other conductor, said pin telescopingly engaging said socket prior to telescopic interengagement of said sleeve and said second conductor.
 7. The electrical connector of claim 6 wherein said conductors comprise two pairs, one conductor in each pair being of opposite polarity from the other conductor in said pair, said pin extending axially from each conductor of one pair, said pins having axially extending grooves on the surface thereof and each conductor of the other pair having radially inwardly extending lugs at the leading ends thereof, the grooves and lugs of one set being of different arrangement than the grooves and lugs of the other set such that in each pair of conductors a conductor of one polarity can be telescopically engaged only with the sleeve on the conductor of similar polarity of the other pair.
 8. The electrical connector of claIm 6 wherein said pin has an axially extending groove thereon and said other conductor has a radially inwardly prjecting lug at the leading end thereof which must register axially with said groove to enable telescopic engagement of said second conductor and said sleeve.
 9. The electrical connector of claim 8 wherein the axially inner end of said groove has a circumferential extension adapted to receive said lug when the lug registers axially with said extension and one of said conductors is rotated about its axis relative to the other conductor.
 10. The electrical connector of claim 9 wherein said circumferential extension is located to register with said lug after said sleeve and the second conductor have telescopically interengaged.
 11. The electrical connector of claim 1 which also comprises first and second housings of nonconductive material which define chambers for said conductors which are generally closed, except at the confronting end faces of said housings, said first housing having a socket opening to the exterior thereof and adapted to telescopically receive a portion of said second housing, said housing socket being dimensioned to have a close fit with said portion of the second housing, one of said housings surrounding said first conductor and the other housing surrounding the second conductor such that when the second housing is fully received in the socket of the first housing the second conductor telescopically engages said petals of said connector sleeve, said housing socket being dimensioned to have a close fit with said portion of said second housing such that when the housings are telescopically disengaged a partial vacuum is created within the housings at the portions thereof enclosing the connected portions of said conductors, the axial extent of said housing socket being dimensioned such that when the housings are telescopically disengaged the petals of said connector sleeve disengage said second other conductor prior to disengagement of said housing socket and said second housing.
 12. The electrical connector of claim 11 which also comprises a wall of a nonconductive material on said housing enclosing said one conductor, said wall being adjacent said end of said petals of said connector sleeve and having a hole therein substantially coaxial with said end of said petals, said pilot pin being carried by said first conductor and extending axially beyond the end thereof and beyond said end of said petals of said connector sleeve, said pilot pin extending coaxially with said hole in said wall, and in which said second conductor has a tubular leading end portion having an outer diameter only slightly smaller than said hole and an inner diameter only slightly greater than said pilot pin, said leading end portion of said second conductor being adapted to extend through said hole, telescope over said pilot pin and engage said end of said petals when said housings are fully telescopically engaged.
 13. The electrical connector of claim 12 wherein said pin extends concentrically into said hole to define an annular opening in said wall for guiding the tubular leading end portion of said second conductor into concentric engagement with the petals of the connector sleeve.
 14. The electrical connector of claim 12 including means on the inner side of said wall surrounding said hole and supporting said ends of said petals concentrically with said hole.
 15. The electrical connector of claim 1 which includes first and second housings of a nonconductive material surrounding said conductors, a single conductor in each of said housings, one of said housings snugly embracing said first conductor and being circumferentially enlarged to accommodate said sleeve and extending axially beyond said sleeve, said enlarged portion of said one housing having an opening at the free end thereof concentric with the axis of the sleeve therein, the other housing snugly embracing said second conductor, the opening in the end of the first housing being dimensioned to snuGly receive the portion of the second conductor surrounded by said second housing so that when said second conductor is engaged with said sleeve the opening in the first housing forms a generally air-tight fit with the outer surface portion of the second housing.
 16. The electrical connector of claim 15 wherein the opening in the first housing has a peripheral, generally radially inwardly extending flexible lip thereon dimensioned to facilitate formation of said generally air-tight fitting with the surface of the first housing.
 17. The electrical connector of claim 12 which also comprises a key mounted in a radially extending predetermined angular orientation in said tubular portion of said second conductor and in which said pin has a slot in a corresponding angular orientation to slidably receive said key.
 18. The electrical connector of claim 17 wherein said nonconductive pin extends coaxially beyond the free end of the first housing to at least the open end thereof, said second conductor being tubular at the free end thereof so that said pin telescopes within said second conductor with a smooth guiding fit as the two housings are interengaged before the free end of the second conductor is engaged by the leading ends of the petals of said sleeve.
 19. The electrical connector of claim 18 wherein said pin has an axially extending groove therein and said second conductor has a radially inwardly extending lug at the free end thereof which must axially align and register with said groove to enable telescopic engagement of said pin and second conductor, the groove and lug arrangement being different for conductors of different voltages and polarities so that only conductors of similar voltages and polarities can be telescopically engaged.
 20. The electrical connector of claim 1 wherein said sleeve connector comprises a tulip connector, each of said petals having a radially outwardly bowed central portion with reversely bent end portions of smaller outer diameter, said end portions having radially outwardly curved ends, the centrally bowed portion of each petal having a greater radial thickness than the reversely bent end portions, the minimum inner diameter of the centrally bowed portion being smaller than the minimum inner diameter of the reversely bent end portions so that, when said second conductor is telescopically engaged with said tulip connector, the outer surface of said second conductor first encounters the inner periphery of the reversely bent end portions and, as the second conductor is further telescoped into said sleeve, the end portion of the second conductor then contacts the inner periphery of the centrally bowed portion.
 21. The electrical connector of claim 20 wherein said inner diameters of said centrally bowed portions are dimensioned such that, when said second conductor is fully telecoped within said sleeve, the reversely bent end portions are radially spaced outwardly from the outer peripheral surface of said second conductor.
 22. An electrical connector comprising a pair of housings each surrounding an end of a conductor, said conductor ends being of tubular shape, one of said conductors having a nonconductive pilot pin extending coaxially beyond the end thereof, a resilient connector sleeve on the end of said one conductor and having one end thereof extending circumferentially around said pilot pin, the housing enclosing said one conductor having an end wall provided with an opening aligned axially with said pin and slightly larger in diameter than said pin, said pin extending into said opening and terminating substantially flush with the outer face of said end wall to define a narrow annular opening in said end wall, said connector sleeve being disposed behind said wall so that said wall and said pin define a dead front on said housing, the end of the other conductor being tubular and adapted to be inserted through said annular opening between the outer end of said pin and opening in said end wall to engage with said end of the resIlient connector sleeve.
 23. The electrical connector of claim 22 including means on the inner side of said wall surrounding said opening and supporting said end of the resilient connector sleeve concentric with the opening.
 24. The electrical connector of claim 22 wherein said connector sleeve comprises a series of petals of arcuate shape in transverse section, said petals being arranged in circumferential fashion with their longitudinal edges in abutting relation, yielding means circumferentially circumscribing said end of said connector sleeve, the opening defined by said end of the connector sleeve being smaller than the outer diameter of the end of said other conductor.
 25. The electrical connector of claim 22 wherein said connector sleeve comprises a series of petals of arcuate shape in transverse section, said petals being arranged in circumferential fashion with their longitudinal edges in abutting relation, yielding means circumferentially circumsribing said end of said connector sleeve, said end wall being perpendicular to the longitudinal axis of the connector sleeve at the portion of its inner face surrounding said opening, means in said one housing adjacent the other end of said connector sleeve forming an abutment perpendicular to the longitudinal axis of said connector sleeve, said petals all being the same length and slightly shorter than the distance between said abutment and said portion of said end wall.
 26. The electrical connector of claim 22 wherein the width of said annular space is not more than about 3/32 inches.
 27. The electrical connector of claim 26 wherein said other conductor has a diameter of at least about 3/4 inches.
 28. A tulip connector for electrically coupling a pair of conductors comprising, a plurality of axially extending conductive petals arranged in generally circular spatial relation and biased radially inwardly to define a generally circular passageway in the connector, one end of said connector being adapted to be telescoped over and frictionally engage the outer cylindrical surface of a conductor having a diameter at least slightly greater than the minimum diameter of the passageway in the connector, each of said petals having a radially outwardly bowed central portion with a reversely bent, radially outwardly extending portion at said one end of the connector, spring means seated within and extending circumferentially around the annular seat formed by the junction of said outwardly bowed portion and said reversely bent end portions of said petals, said reversely bent end portions being thinner than the portion of the outwardly bowed portion of the petal spaced axially inwardly of said junction, the radially inner surfaces of the outwardly bowed portions being curved radially outwardly to intersect with the radially inner surfaces of said reversely bent end portions at said junction so that the minimum inner diameter of the outwardly bowed portions is smaller than the inner diameter of said junction, the diameter of the portion of the passageway defined by the radially inner surfaces of the reversely bent end portions being substantially greater at the free ends of said end portions than at said junction so that, when said conductor with said cylindrical outer surface is telescopically engaged with said one end of the connector, the outer surface of the conductor first encounters the inner periphery of the reversely bent end portions and, as the conductor is further telescoped into said connector, the leading end of the conductor thereafter contacts the inner periphery of the connector at said portion of the passageway of minimum diameter which is spaced axially inwardly of said junction and causes the connector to circumferentially enlarge to thereby displace the radially inner surfaces of said petals at said junction radially outwardly from the outer surface of the conductor.
 29. A tulip connector as called for in claim 28 wherein the configuration of the other end of each petal is substantially The same as said one end.
 30. A tulip connector as called for in claim 28 wherein the inner surfaces of the outwardly bowed portion and the reversely bent end portion of each petal are shaped to form a sharp line of intersection at said junction.
 31. A tulip connector as called for in claim 28 wherein the inner surface of each petal at said junction is defined by the line of intersection between oppositely inclined surfaces.
 32. A tulip connector as called for in claim 28 wherein the inner surface of each petal at said junction is defined by the intersection between surfaces which are inclined relative to one another in a direction axially of said passageway. 